Regional conduction velocities determined by noninvasive mapping are associated with arrhythmia-free survival after atrial fibrillation ablation.

BACKGROUND: Atrial arrhythmogenic substrate is a key determinant of atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI), and reduced conduction velocities have been linked to adverse outcome. However, a noninvasive method to assess such electrophysiologic substrate is not available to date. OBJECTIVE: This study aimed to noninvasively assess regional conduction velocities and their association with arrhythmia-free survival after PVI. METHODS: A consecutive 52 patients scheduled for AF ablation (PVI only) and 19 healthy controls were prospectively included and received electrocardiographic imaging (ECGi) to noninvasively determine regional atrial conduction velocities in sinus rhythm. A novel ECGi technology obviating the need of additional computed tomography or cardiac magnetic resonance imaging was applied and validated by invasive mapping. RESULTS: Mean ECGi-determined atrial conduction velocities were significantly lower in AF patients than in healthy controls (1.45 ± 0.15 m/s vs 1.64 ± 0.15 m/s; P < .0001). Differences were particularly pronounced in a regional analysis considering only the segment with the lowest average conduction velocity in each patient (0.8 ± 0.22 m/s vs 1.08 ± 0.26 m/s; P < .0001). This average conduction velocity of the "slowest" segment was independently associated with arrhythmia recurrence and better discriminated between PVI responders and nonresponders than previously proposed predictors, including left atrial size and late gadolinium enhancement (magnetic resonance imaging). Patients without slow-conduction areas (mean conduction velocity <0.78 m/s) showed significantly higher 12-month arrhythmia-free survival than those with 1 or more slow-conduction areas (88.9% vs 48.0%; P = .002). CONCLUSION: This is the first study to investigate regional atrial conduction velocities noninvasively. The absence of ECGi-determined slow-conduction areas well discriminates PVI responders from nonresponders. Such noninvasive assessment of electrical arrhythmogenic substrate may guide treatment strategies and be a step toward personalized AF therapy.

CACS, CCTA and mCAD-LT score in the pre-transplant assessment of coronary artery disease and the prediction of post-transplant cardiovascular events.

BACKGROUND: The optimal cardiovascular assessment of liver transplant (LT) candidates is unclear. We aimed to evaluate the performance of CT-based coronary tests (coronary artery calcium score [CACS] and coronary CT angiography [CCTA]) and a modification of the CAD-LT score (mCAD-LT, excluding family history of CAD) to diagnose significant coronary artery disease (CAD) before LT and predict the incidence of post-LT cardiovascular events (CVE). METHODS: We retrospectively analysed a single-centre cohort of LT candidates who underwent non-invasive tests; invasive coronary angiography (ICA) was performed depending on the results of non-invasive tests. mCAD-LT was calculated in all patients. RESULTS: Six-hundred-and-thirty-four LT candidates were assessed and 351 of them underwent LT. CACS, CCTA and ICA were performed in 245, 123 and 120 LT candidates, respectively. Significant CAD was found in 30% of patients undergoing ICA. The AUROCs of mCAD-LT (.722) and CCTA (.654) were significantly higher than that of CACS (.502) to predict the presence of significant CAD. Specificity of the tests ranged between 31% for CCTA and 53% for CACS. Among patients who underwent LT, CACS ≥ 400 and mCAD-LT were independently associated with the incidence of CVE; in patients who underwent CCTA before LT, significant CAD at CCTA also predicted post-LT CVE. CONCLUSION: In this cohort, mCAD-LT score and CT-based tests detect the presence of significant CAD in LT candidates, although they tend to overestimate it. Both mCAD-LT score and CT-based tests classify LT recipients according to their risk of post-LT CVE and can be used to improve post-LT risk mitigation.

Combined Area of Left and Right Atria May Outperform Atrial Volumes as a Predictor of Recurrences after Ablation in Patients with Persistent Atrial Fibrillation-A Pilot Study.

Background and Objectives: Left atrial (LA) remodelling and dilatation predicts atrial fibrillation (AF) recurrences after catheter ablation. However, whether right atrial (RA) remodelling and dilatation predicts AF recurrences after ablation has not been fully evaluated. Materials and Methods: This is an observational study of 85 consecutive patients (aged 57 ± 9 years; 70 [82%] men) who underwent cardiac magnetic resonance before first catheter ablation for AF (40 [47.1%] persistent AF). Four-chamber cine-sequence was selected to measure LA and RA area, and ventricular end-systolic image phase to obtain atrial 3D volumes. The effect of different variables on event-free survival was investigated using the Cox proportional hazards model. Results: In patients with persistent AF, combined LA and RA area indexed to body surface area (AILA + RA) predicted AF recurrences (HR = 1.08, 95% CI 1.00-1.17, p = 0.048). An AILA + RA cut-off value of 26.7 cm2/m2 had 72% sensitivity and 73% specificity for predicting recurrences in patients with persistent AF. In this group, 65% of patients with AILA + RA > 26.7 cm2/m2 experienced AF recurrence within 2 years of follow-up (median follow-up 11 months), compared to 25% of patients with AILA + RA ≤ 26.7 cm2/m2 (HR 4.28, 95% CI 1.50-12.22; p = 0.007). Indices of LA and RA dilatation did not predict AF recurrences in patients with paroxysmal AF. Atrial 3D volumes did not predict AF recurrences after ablation. Conclusions: In this pilot study, the simple measurement of AILA + RA may predict recurrences after ablation of persistent AF, and may outperform measurements of atrial volumes. In paroxysmal AF, atrial dilatation did not predict recurrences. Further studies on the role of RA and LA remodelling are needed.

Post-Ablation cardiac Magnetic resonance to assess Ventricular Tachycardia recurrence (PAM-VT study).

AIMS: Conducting channels (CCs) detected by late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) are related to ventricular tachycardia (VT). The aim of this work was to study the ability of post-ablation LGE-CMR to evaluate ablation lesions. METHODS AND RESULTS: This is a prospective study of consecutive patients referred for a scar-related VT ablation. LGE-CMR was performed 6-12 months prior to ablation and 3-6 months after ablation. Scar characteristics of pre- and post-ablation LGE-CMR were compared. During the study period (March 2019-April 2021), 61 consecutive patients underwent scar-related VT ablation after LGE-CMR. Overall, 12 patients were excluded (4 had poor-quality LGE-CMR, 2 died before post-ablation LGE-CMR, and 6 underwent post-ablation LGE-CMR 12 months after ablation). Finally, 49 patients (age: 65.5 ± 9.8 years, 97.9% male, left ventricular ejection fraction: 34.8 ± 10.4%, 87.7% ischaemic cardiomyopathy) were included. Post-ablation LGE-CMR showed a decrease in the number (3.34 ± 1.03 vs. 1.6 ± 0.2; P < 0.0001) and mass (8.45 ± 1.3 vs. 3.5 ± 0.6 g; P < 0.001) of CCs. Arrhythmogenic CCs disappeared in 74.4% of patients. Dark core was detected in 75.5% of patients, and its presence was not related to CC reduction (52.2 ± 7.4% vs. 40.8 ± 10.6%, P = 0.57). VT recurrence after one year follow-up was 16.3%. The presence of two or more channels in the post-ablation LGE-CMR was a predictor of VT recurrence (31.82% vs. 0%, P = 0.0038) with a sensibility of 100% and specificity of 61% (area under the curve 0.82). In the same line, a reduction of CCs < 55% had sensibility of 100% and specificity of 61% (area under the curve 0.83) to predict VT recurrence. CONCLUSION: Post-ablation LGE-CMR is feasible, and a reduction in the number of CCs is related with lower risk of VT recurrence. The dark core was not present in all patients. A decrease in VT substrate was also observed in patients without a dark core area in the post-ablation LGE-CMR.

Association of central obesity with unique cardiac remodelling in young adults born small for gestational age.

AIMS: Being born small for gestational age (SGA, 10% of all births) is associated with increased risk of cardiovascular mortality in adulthood together with lower exercise tolerance, but mechanistic pathways are unclear. Central obesity is known to worsen cardiovascular outcomes, but it is uncertain how it affects the heart in adults born SGA. We aimed to assess whether central obesity makes young adults born SGA more susceptible to cardiac remodelling and dysfunction. METHODS AND RESULTS: A perinatal cohort from a tertiary university hospital in Spain of young adults (30-40 years) randomly selected, 80 born SGA (birth weight below 10th centile) and 75 with normal birth weight (controls) was recruited. We studied the associations between SGA and central obesity (measured via the hip-to-waist ratio and used as a continuous variable) and cardiac regional structure and function, assessed by cardiac magnetic resonance using statistical shape analysis. Both SGA and waist-to-hip were highly associated to cardiac shape (F = 3.94, P < 0.001; F = 5.18, P < 0.001 respectively) with a statistically significant interaction (F = 2.29, P = 0.02). While controls tend to increase left ventricular end-diastolic volumes, mass and stroke volume with increasing waist-to-hip ratio, young adults born SGA showed a unique response with inability to increase cardiac dimensions or mass resulting in reduced stroke volume and exercise capacity. CONCLUSION: SGA young adults show a unique cardiac adaptation to central obesity. These results support considering SGA as a risk factor that may benefit from preventive strategies to reduce cardiometabolic risk.

Predictive value of late gadolinium enhancement cardiovascular magnetic resonance in patients with persistent atrial fibrillation: dual-centre validation of a standardized method.

Aims: With recurrence rates up to 50% after pulmonary vein isolation (PVI) in persistent atrial fibrillation (AF), predictive tools to improve patient selection are needed. Patient selection based on left atrial late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) has been proposed previously (UTAH-classification). However, this approach has not been widely established, in part owed to the lack of standardization of the LGE quantification method. We have recently established a standardized LGE-CMR method enabling reproducible LGE-quantification. Here, the ability of this method to predict outcome after PVI was evaluated. Methods and results: This dual-centre study (n = 219) consists of a prospective derivation cohort (n = 37, all persistent AF) and an external validation cohort (n = 182; 66 persistent, 116 paroxysmal AF). All patients received an LGE-CMR prior to first-time PVI-only ablation. LGE was quantified based on the signal-intensity-ratio relative to the blood pool, applying a uniform LGE-defining threshold of >1.2.  In patients with persistent AF in the derivation cohort, left atrial LGE-extent above a cut-off value of 12% was found to best predict relevant low-voltage substrate (≥2 cm two with <0.5 mV during sinus rhythm) and arrhythmia-free survival 12 months post-PVI. When applied to the external validation cohort, this cut-off value was also predictive of arrhythmia-free survival for both, the total cohort and the subgroup with persistent AF (LGE < 12%: 80% and 76%; LGE > 12%: 55% and 44%; P = 0.007 and P = 0.029, respectively). Conclusion: This dual-centre study established and validated a standardized, reproducible LGE-CMR method discriminating PVI responders from non-responders, which may improve choice of therapeutic approach or ablation strategy for patients with persistent AF.

Magnetic resonance in patients with cardiovascular devices. SEC-GT CRMTC/SEC-Heart Rhythm Association/SERAM/SEICAT consensus document.

Magnetic resonance has become a first-line imaging modality in various clinical scenarios. The number of patients with different cardiovascular devices, including cardiac implantable electronic devices, has increased exponentially. Although there have been reports of risks associated with exposure to magnetic resonance in these patients, the clinical evidence now supports the safety of performing these studies under specific conditions and following recommendations to minimize possible risks. This document was written by the Working Group on Cardiac Magnetic Resonance Imaging and Cardiac Computed Tomography of the Spanish Society of Cardiology (SEC-GT CRMTC), the Heart Rhythm Association of the Spanish Society of Cardiology (SEC-Heart Rhythm Association), the Spanish Society of Medical Radiology (SERAM), and the Spanish Society of Cardiothoracic Imaging (SEICAT). The document reviews the clinical evidence available in this field and establishes a series of recommendations so that patients with cardiovascular devices can safely access this diagnostic tool.

Quantification of right atrial fibrosis by cardiac magnetic resonance: verification of the method to standardize thresholds.

INTRODUCTION AND OBJECTIVES: Late gadolinium-enhanced cardiac magnetic resonance (LGE-CMR) allows noninvasive detection of left atrial fibrosis in patients with atrial fibrillation (AF). However, whether the same methodology can be used in the right atrium (RA) remains unknown. Our aim was to define a standardized threshold to characterize RA fibrosis in LGE-CMR. METHODS: A 3 Tesla LGE-CMR was performed in 53 individuals; the RA was segmented, and the image intensity ratio (IIR) calculated for the RA wall using 1 557 767 IIR pixels (40 994±10 693 per patient). The upper limit of normality of the IIR (mean IIR+2 standard deviations) was estimated in healthy volunteers (n=9), and patients who had undergone previous typical atrial flutter ablation (n=9) were used to establish the dense scar threshold. Paroxysmal and persistent AF patients (n=10 each) were used for validation. IIR values were correlated with a high-density bipolar voltage map in 15 patients undergoing AF ablation. RESULTS: The upper normality limit (total fibrosis threshold) in healthy volunteers was set at an IIR = 1.21. In the postablation group, 60% of the maximum IIR pixel (dense fibrosis threshold) was calculated as IIR = 1.29. Endocardial bipolar voltage showed a weak but significant correlation with IIR. The overall accuracy between the electroanatomical map and LGE-CMR to characterize fibrosis was 56%. CONCLUSIONS: An IIR > 1.21 was determined to be the threshold for the detection of right atrial fibrosis, while an IIR > 1.29 differentiates interstitial fibrosis from dense scar. Despite differences between the left and right atria, fibrosis could be assessed with LGE-CMR using similar thresholds in both chambers.

Progressive and Simultaneous Right and Left Atrial Remodeling Uncovered by a Comprehensive Magnetic Resonance Assessment in Atrial Fibrillation.

Background Left atrial structural remodeling contributes to the arrhythmogenic substrate of atrial fibrillation (AF), but the role of the right atrium (RA) remains unknown. Our aims were to comprehensively characterize right atrial structural remodeling in AF and identify right atrial parameters predicting recurrences after ablation. Methods and Results A 3.0 T late gadolinium enhanced-cardiac magnetic resonance was obtained in 109 individuals (9 healthy volunteers, 100 patients with AF undergoing ablation). Right and left atrial volume, surface, and sphericity were quantified. Right atrial global and regional fibrosis burden was assessed with validated thresholds. Patients with AF were systematically followed after ablation for recurrences. Progressive right atrial dilation and an increase in sphericity were observed from healthy volunteers to patients with paroxysmal and persistent AF; fibrosis was similar among the groups. The correlation between parameters recapitulating right atrial remodeling was mild. Subsequently, remodeling in both atria was compared. The RA was larger than the left atrium (LA) in all groups. Fibrosis burden was higher in the LA than in the RA of patients with AF, whereas sphericity was higher in the LA of patients with persistent AF only. Fibrosis, volume, and surface of the RA and LA, but not sphericity, were strongly correlated. Tricuspid regurgitation predicted right atrial volume and shape, whereas diabetes was associated with right atrial fibrosis burden; sex and persistent AF also predicted right atrial volume. Fibrosis in the RA was mostly located in the inferior vena cava-RA junction. Only right atrial sphericity is significantly associated with AF recurrences after ablation (hazard ratio, 1.12 [95% CI, 1.01-1.25]). Conclusions AF progression associates with right atrial remodeling in parallel with the LA. Right atrial sphericity yields prognostic significance after ablation.

Sex as a main determinant of bi-atrial acute and chronic adaptation to exercise.

PURPOSE: Athlete's heart encompasses multiple physiological cardiac adaptations, although less is known at atrial level. How sex may influence the type and extent of atrial adaptations to exercise stimuli is also unknown. Our objective was to compare gender differences of echocardiographic atrial function indices in response to exercise in endurance athletes (EAs). METHODS: Highly trained (> 10 h/week) endurance athletes performed a maximal cardiopulmonary exercise test (CPET). Echocardiographic evaluation was performed at rest and immediately after exercise. Atria analysis consisted of standard and speckle-tracking echocardiographic assessment of atrial dimensions and contractile, reservoir, and conduit functions with myocardial deformation. RESULTS: 80 EAs (55% women) were enrolled and performed excellent CPET (129.6% of predicted VO2 maximal consumption). At rest, left atrial (LA) volumes and strain were similar between men and women. Women had lower right atrial (RA) volumes (26.7 vs 32.9 ml/m2, p < 0.001) and higher reservoir and conduit strain absolute values. After exercise, women exhibited a larger improvement in reservoir and conduit LA strain, and the same trend was observed for the RA. In EAs with LA dilatation on baseline (~ 50%), women persistently showed higher increase in reservoir and conduit strain profile with exercise compared to men. CONCLUSION: In highly trained EAs, women have similar or even lower atrial dimensions remodelling compared to men, but better function based on reservoir and conduit strain values both at rest and in response to exercise. This phenomenon should be confirmed in larger studies and its potential role in the development of supraventricular arrhythmias, addressed in a specifically designed protocol.

Non-invasive isthmus identification of complex arrhythmias in congenital heart disease.

Sustained re-entrant tachyarrhythmias treatment has become pivotal in the grown-up congenital heart patients clinical management. Cardiac LGE-MRI tissue characterization integrated with high definition electroanatomic map could allow fast recognition and effective treatment of substrate of tachyarrhythmias. Cardiac LGE-MRI areas were suggestive of post-surgical changes both in atrium and ventricle. High-density electro-anatomical map localized areas of slow conduction identifying conducting isthmuses of re-entrant arrhythmias.

Cardiac and Pulmonary Vascular Remodeling in Endurance Open Water Swimmers Assessed by Cardiac Magnetic Resonance: Impact of Sex and Sport Discipline.

Background: The cardiac response to endurance exercise has been studied previously, and recent reports have described the extension of this remodeling to the pulmonary vasculature. However, these reports have focused primarily on land-based sports and few data are available on exercise-induced cardio-pulmonary adaptation in swimming. Nor has the impact of sex on this exercise-induced cardio-pulmonary remodeling been studied in depth. The main aim of our study was to evaluate cardiac and pulmonary circulation remodeling in endurance swimmers. Among the secondary objectives, we evaluate the impact of sex and endurance sport discipline on this cardio-pulmonary remodeling promoted by exercise training. Methods:Resting cardiovascular magnetic resonance imaging was performed in 30 healthy well-trained endurance swimmers (83.3% male) and in 19 terrestrial endurance athletes (79% male) to assess biventricular dimensions and function. Pulmonary artery dimensions and flow as well as estimates of pulmonary vascular resistance (PVR) were also evaluated. Results:In relation to the reference parameters for the non-athletic population, male endurance swimmers had larger biventricular and pulmonary artery size (7.4 ± 1.0 vs. 5.9 ± 1.1 cm2, p < 0.001) with lower biventricular ejection fraction (EF) (left ventricular (LV) EF: 58 ± 4.4 vs. 67 ± 4.5 %, p < 0.001; right ventricular (RV) EF: 60 ± 4 vs. 66 ± 6 %, p < 0.001), LV end-diastolic volume (EDV): 106 ± 11 vs. 80 ± 9 ml/m2, p < 0.001; RV EDV: 101 ± 14 vs. 83 ± 12 ml/m2, p < 0.001). Significantly larger LV volume and lower LV EF were also observed in female swimmers (LV EF: 60 ± 5.3 vs. 67 ± 4.6 %, p = 0.003; LV EDV: 90 ± 17.6 vs. 75± 8.7 ml/m2, p = 0.002). Compared to terrestrial endurance athletes, swimmers showed increased LV indexed mass (75.0 ± 12.8 vs. 61.5 ± 10.0 g/m2, p < 0.001). The two groups of endurance athletes had similar pulmonary artery remodeling. Conclusions: Cardiac response to endurance swimming training implies an adaptation of both ventricular and pulmonary vasculature, as in the case of terrestrial endurance athletes. Cardio-pulmonary remodeling seems to be less extensive in female than in male swimmers.

Outcomes of Septal Myectomy beyond 65 Years, with and without Concomitant Procedures.

INTRODUCTION AND OBJECTIVES: Septal myectomy remains the first septal reduction therapy for hypertrophic obstructive cardiomyopathy in young patients and those requiring concomitant procedures. Its role in advanced ages is questioned due to perceived increased risk. We assess the outcomes of surgical relief of obstruction in patients beyond 65 years old. METHODS: A single-center retrospective review of patients ≥ 65 years old undergoing septal myectomy through median sternotomy between April 2015 and February 2020. RESULTS: We identified 52 patients. Mean age was 71.8 ± 4.9 years; 36 (69.2%) were females. All were symptomatic. Mean highest LVOT gradient was 90 ± 39 mmHg. All patients had systolic anterior motion (SAM) of the mitral valve and 36 (69.2%) ≥ moderate mitral regurgitation. Additional LVOT interventions beyond myectomy were performed in 34 (65.4%). At least one other cardiac concomitant procedure was performed 44 (84.6%). No perioperative mortality in elective surgery occurred. One patient (1.9%) developed atrio-ventricular block. Postoperative mean gradient was 4.3 ± 1.9 mmHg, with 46 (88.4%) achieving complete resolution of obstruction. Mitral regurgitation was reduced to grade ≤ I in 46 (88.5%). Mean follow-up time was 2.3 ± 1.2 years and 82% of patients were in NYHA I. Survival at 2 years was 98%. CONCLUSION: Septal myectomy in the elderly is a safe and effective operation despite the need for concomitant procedures. LVOT interventions beyond septal myectomy to relieve obstruction are common in this advanced cohort of hypertrophic cardiomyopathy patients. This operation carried at experienced centers seems an unmatched therapeutic option.

Exercise Capacity in Young Adults Born Small for Gestational Age.

Importance: Being born small for gestational age (SGA), approximately 10% of all births, is associated with increased risk of cardiovascular mortality in adulthood, but mechanistic pathways are unclear. Cardiac remodeling and dysfunction occur in fetuses SGA and children born SGA, but it is uncertain whether and how these changes persist into adulthood. Objective: To evaluate baseline cardiac function and structure and exercise capacity in young adults born SGA. Design, Setting, and Participants: This cohort study conducted from January 2015 to January 2018 assessed a perinatal cohort born at a tertiary university hospital in Spain between 1975 and 1995. Participants included 158 randomly selected young adults aged 20 to 40 years born SGA (birth weight below the 10th centile) or with intrauterine growth within standard reference ranges (controls). Participants provided their medical history, filled out questionnaires regarding smoking and physical activity habits, and underwent incremental cardiopulmonary exercise stress testing, cardiac magnetic resonance imaging, and a physical examination, with blood pressure, glucose level, and lipid profile data collected. Exposure: Being born SGA. Main Outcomes and Measures: Cardiac structure and function assessed by cardiac magnetic resonance imaging, including biventricular end-diastolic shape analysis. Exercise capacity assessed by incremental exercise stress testing. Results: This cohort study included 81 adults born SGA (median age at study, 34.4 years [IQR, 30.8-36.7 years]; 43 women [53%]) and 77 control participants (median age at study, 33.7 years [interquartile range (IQR), 31.0-37.1 years]; 33 women [43%]). All participants were of White race/ethnicity and underwent imaging, whereas 127 participants (80% of the cohort; 66 control participants and 61 adults born SGA) completed the exercise test. Cardiac shape analysis showed minor changes at rest in right ventricular geometry (DeLong test z, 2.2098; P = .02) with preserved cardiac function in individuals born SGA. However, compared with controls, adults born SGA had lower exercise capacity, with decreased maximal workload (mean [SD], 180 [62] W vs 214 [60] W; P = .006) and oxygen consumption (median, 26.0 mL/min/kg [IQR, 21.5-33.5 mL/min/kg vs 29.5 mL/min/kg [IQR, 24.0-36.0 mL/min/kg]; P = .02). Exercise capacity was significantly correlated with left ventricular mass (ρ = 0.7934; P < .001). Conclusions and Relevance: This cohort of young adults born SGA had markedly reduced exercise capacity. These results support further research to clarify the causes of impaired exercise capacity and the potential association with increased cardiovascular mortality among adults born SGA.

Atrioventricular plane displacement versus mitral and tricuspid annular plane systolic excursion: A comparison between cardiac magnetic resonance and M-mode echocardiography.

INTRODUCTION: Both echocardiography and CMR imaging are used to quantify longitudinal function. Inter-method variability for mitral (MAPSE) and tricuspid (TAPSE) annular plane systolic excursion, and variability between directly measured MAPSE and TAPSE and as based on atrioventricular plane displacement (AVPD) analysis by CMR, are, however, not known. This study, therefore, assessed inter-method variability and variability between annular plane systolic excursion and AVPD-based values in a healthy adult population. METHODS: Echocardiography and CMR were performed in 111 adults (35 [32-38] years). Method comparisons were assessed with Deming regression, Bland-Altman analysis and coefficient of variation. Observer reproducibility was assessed by the concordance correlation coefficient. RESULTS: Echocardiography and semi-automatic CMR agreed on MAPSE (17 ± 2 mm vs. 17 ± 2 mm, p = 0.1) and TAPSE (25 ± 3 mm vs. 25 ± 3 mm, p = 0.5), correlated highly between methods (fitted-slope 1.22 [95% CI 1.07-1.38] and 1.12 [95% CI 0.95-1.29]) and showed low bias (0.42 [95% CI - 2.05 to 2.88] and - 0.18 [95% CI - 4.78 to 4.43]). Intra-/inter-observer reproducibility was high for both methods for both MAPSE (echocardiography 0.96/0.86; CMR 0.87/0.85) and TAPSE (echocardiography 0.96/0.95; CMR 0.97/0.96). MAPSE (16 ± 2 mm vs. 17 ± 2 mm; p < 0.001) and TAPSE (24 ± 3 vs. 25 ± 3 mm; p < 0.001) based on AVPD were similar but statistically different compared with semi-automatic CMR. CONCLUSIONS: Echocardiography and semi-automatic CMR have low variability and provide similar values for MAPSE and TAPSE and are thus interchangeable for follow-up studies. Lateral values based on tracked data from AVPD analysis are not clinically significantly different and could be used as a representation of annular displacement.

Magnetic Resonance Imaging-Guided Fibrosis Ablation for the Treatment of Atrial Fibrillation: The ALICIA Trial.

BACKGROUND: Myocardial fibrosis is key for atrial fibrillation maintenance. We aimed to test the efficacy of ablating cardiac magnetic resonance (CMR)-detected atrial fibrosis plus pulmonary vein isolation (PVI). METHODS: This was an open-label, parallel-group, randomized, controlled trial. Patients with symptomatic drug-refractory atrial fibrillation (paroxysmal and persistent) undergoing first or repeat ablation were randomized in a 1:1 basis to receive PVI plus CMR-guided fibrosis ablation (CMR group) or PVI alone (PVI-alone group). The primary end point was the rate of recurrence (>30 seconds) at 12 months of follow-up using a 12-lead ECG and Holter monitoring at 3, 6, and 12 months. The analysis was conducted by intention-to-treat. RESULTS: In total, 155 patients (71% male, age 59±10, CHA2DS2-VASc 1.3±1.1, 54% paroxysmal atrial fibrillation) were allocated to the PVI-alone group (N=76) or CMR group (N=79). First ablation was performed in 80% and 71% of patients in the PVI-alone and CMR groups, respectively. The mean atrial fibrosis burden was 12% (only ≈50% of patients had fibrosis outside the pulmonary vein area). One hundred percent and 99% of patients received the assigned intervention in the PVI-alone and CMR group, respectively. The primary outcome was achieved in 21 patients (27.6%) in the PVI-alone group and 22 patients (27.8%) in the CMR group (odds ratio: 1.01 [95% CI, 0.50-2.04]; P=0.976). There were no differences in the rate of adverse events (3 in the CMR group and 2 in the PVI-alone group; P=0.68). CONCLUSIONS: A pragmatic ablation approach targeting CMR-detected atrial fibrosis plus PVI was not more effective than PVI alone in an unselected population undergoing atrial fibrillation ablation with low fibrosis burden. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02698631.

Handling confounding variables in statistical shape analysis - application to cardiac remodelling.

Statistical shape analysis is a powerful tool to assess organ morphologies and find shape changes associated to a particular disease. However, imbalance in confounding factors, such as demographics might invalidate the analysis if not taken into consideration. Despite the methodological advances in the field, providing new methods that are able to capture complex and regional shape differences, the relationship between non-imaging information and shape variability has been overlooked. We present a linear statistical shape analysis framework that finds shape differences unassociated to a controlled set of confounding variables. It includes two confounding correction methods: confounding deflation and adjustment. We applied our framework to a cardiac magnetic resonance imaging dataset, consisting of the cardiac ventricles of 89 triathletes and 77 controls, to identify cardiac remodelling due to the practice of endurance exercise. To test robustness to confounders, subsets of this dataset were generated by randomly removing controls with low body mass index, thus introducing imbalance. The analysis of the whole dataset indicates an increase of ventricular volumes and myocardial mass in athletes, which is consistent with the clinical literature. However, when confounders are not taken into consideration no increase of myocardial mass is found. Using the downsampled datasets, we find that confounder adjustment methods are needed to find the real remodelling patterns in imbalanced datasets.